wxTreeCtrl not wxListCtrl

[Krzysztof Kaczkowski]

Hello
Im  having problem, my class inherit in wxTreeItemData.
(Python2.3 i wxPython2.4.1.2u)

class MyTreeItemData (wxTreeItemData):
    def __init__(self, name):
        wxTreeItemData.__init__(self)
        self.name_key = name
    def TEST():
        pass

  part my class MywxListCtrl inherit in wxTreeCtrl:

  item_data = MyTreeItemData('Test')
  itm = self.AppendItem(a1, a2, -1,-1,item_data)
  print dir(self.GetItemData(itm))

and my problem:
Function dir(self.GetItemData(itm)) not list MyTreeItemData, MyTreeItemData
not assign, dir(...) list only default class wxTreeItemData why?

>  print dir(self.GetItemData(itm))
['Destroy', 'GetClassName', 'GetData', 'GetId', 'SetData', 'SetId',
'__doc__', '__init__', '__module__', '__repr__', 'this', 'thisown']


>print dir(item_data)
['Destroy', 'GetClassName', 'GetData', 'GetId', 'SetData', 'SetId', 'TEST',
'__doc__', '__init__', '__module__', '__repr__', 'name_key', 'this',
'thisown']

Thank you.